Question

The reaction equation of the preparation of HCl by synthesis is given by:
A.$NaCl\,+\,{{H}_{2}}S{{O}_{4}}\,\to \,NaHS{{O}_{4}}\,+\,HCl$
B.$NaHS{{O}_{4}}\,+\,NaCl\,\to \,HCl\,+\,NaS{{O}_{4}}$
C.${{H}_{2}}\,+\,C{{l}_{2}}\,\to \,2HCl$
D.None of these

Answer 1

The compound in the given question is Hydrogen chloride. The compound hydrogen chloride has the chemical formula $HCl$ and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor.

Complete step by step answer:
In all the above options we get to see that one of the products is hydrochloric acid. But we have to see only the reaction in which there is preparation of $HCl$ by synthesis.
For preparation of $HCl$ by synthesis we use the chlor alkali process.
In the chlor alkali process, brine (mixture of sodium chloride and water) solution is electrolyzed producing chlorine ($C{{l}_{2}}$​), sodium hydroxide, and hydrogen $(H_2​)$:
$2NaCl\,+\,2{{H}_{2}}O\,\to \,C{{l}_{2}}\,+\,2NaOH\,+\,{{H}_{2}}$
The pure chlorine gas can be combined with hydrogen to produce hydrogen chloride in the presence of UV light:$C{{l}_{2}}(g)\,+\,{{H}_{2}}(g)\,\to \,2HCl(g)$
As the reaction is exothermic, the installation is called an$HCl$ oven or $HCl$ burner. The resulting hydrogen chloride gas is absorbed in deionized water, resulting in chemically pure hydrochloric acid. This reaction can give a very pure product, e.g. for use in the food industry.

Hence, option C is correct.

Additional information:
Hydrochloric acid is the water-based, or aqueous, solution of hydrogen chloride gas. It is also the main component of gastric acid, an acid produced naturally in the human stomach to help digest food. It's used industrially to process steel, the material of choice for suspension bridges and cars and trucks. Hydrochloric acid is also used in the production of batteries, photoflash bulbs and fireworks. It's even used to process sugar and make gelatin.

Note:
Hydrochloric acid is the simplest chlorine-based acid system containing water. It is a solution of hydrogen chloride and water, and a variety of other chemical species, including hydronium and chloride ions. It is a naturally-occurring component of the gastric acid produced in the digestive systems of most animal species, including humans.